Predictive factors for the long-term use of pirfenidone in patients with fibrosing interstitial lung disease

Pirfenidone is an anti-fibrotic agent approved for idiopathic pulmonary fibrosis (IPF), and long-term treatment data and the effect of continuation after disease progression have been reported. The efficacy and safety of pirfenidone in fibrosing interstitial lung disease (ILD) patients without IPF have been recently reported in clinical trials; therefore, the benefits of long-term treatment are also expected. This study aims to analyze the long-term treatment data of pirfenidone and clarify the predictive factors for long-term use of pirfenidone in non-IPF patients. We retrospectively reviewed the records of consecutive fibrosing ILD patients who started using pirfenidone between 2008 and 2014. Of the 266 fibrosing ILD patients, 167 patients had IPF, and 99 had non-IPF. Despite the non-significant differences in body size and pulmonary function between IPF and non-IPF patients, the non-IPF patients had better overall survival than the IPF patients (median 4.06 years vs. 2.09 years, p